A robust PN code tracking algorithm for frequency selective Rayleigh-fading channels

Mohamed El-Tarhuni, Ali Ghrayeb

Research output: Contribution to journalArticle

8 Citations (Scopus)


In this letter, we propose a new tracking scheme that is robust against multipath fading for pseudonoise (PN) code tracking in direct-sequence-spread spectrum systems. The proposed scheme employs an adaptive filter whose taps are adapted using a block least-mean square algorithm and it results in minimizing the effect of multipath interference on the tracking performance. We show that the mean-squared tracking error performance of the proposed scheme is not affected by the presence of closely spaced paths (e.g., one to three chips), unlike that of conventional delay locked loops. We also show that the tap-weight distribution of the filter provides accurate estimates of the multipath delays. For example, at Eb/ N0/ = 5 dB, 98% of the time the path estimates lie within one sample (1/5 of a chip) from the actual delays. Furthermore, simulation results suggest that multipath delays over a wide range of terminal speeds can be tracked successfully. The proposed scheme is well suited for wideband code-division multiple-access systems where a large number of closely-spaced multipath components need to be tracked and used in RAKE combining.

Original languageEnglish
Pages (from-to)1018-1023
Number of pages6
JournalIEEE Transactions on Wireless Communications
Issue number4
Publication statusPublished - 1 Jul 2004



  • Adaptive filters
  • Code acquisition
  • Multipath fading
  • Pseudonoise (PN) code tracking
  • Spread-spectrum communication

ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics

Cite this